Bushing arm deformation mechanism

ABSTRACT

A medical device includes (a) a capsule including a lumen extending therethrough, a proximal end of the capsule including at least one window extending therethrough; (b) a bushing including a channel extending therethrough, a distal end including at least one arm extending distally therefrom such that a corresponding one of the arms is releasably engagable with a corresponding one of the windows; and (c) a core member including a locking portion and at least one engaging element. The locking portion is sized and shaped to be received within the channel of the bushing to apply a pressure to the arm such that the arm engages the windows. The engaging element extends laterally outward from a portion of the core member such that the engaging element engages a corresponding one of the arms to deform the arms radially inward and out of engagement with the windows.

PRIORITY CLAIM

This application claims the priority to the U.S. Provisional ApplicationSer. No. 61/644,780, entitled “BUSHING ARM DEFORMATION MECHANISM” filedon May 9, 2012. The specification of the above-identified application isincorporated herewith by reference.

BACKGROUND

Pathologies of the gastrointestinal (“GI”) system, the biliary tree, thevascular system and other body lumens and hollow organs are oftentreated through endoscopic procedures, many of which require activeand/or prophylactic hemostasis to control bleeding. Hemostasis clips areoften deployed via endoscopes to stop internal bleeding by holdingtogether edges of wounds or incisions to allow natural healing processesto close the wound. Specialized endoscopic clipping devices are used todeploy the clips at desired locations of the body after which the clipdelivery device is withdrawn, leaving the clip within the body.

SUMMARY OF THE INVENTION

The present invention relates to a medical device including a releasemechanism, comprising a capsule extending longitudinally from a proximalend to a distal end and including a lumen extending therethrough, theproximal end of the capsule including a plurality of windows extendingtherethrough and a bushing extending from a proximal end to a distal endand including a channel extending therethrough, the distal end includinga plurality of arms extending distally therefrom such that acorresponding one of the arms is releasably engagable with acorresponding one of the windows of the capsule along with a core memberincluding a locking portion and a plurality of engaging elements, thelocking portion sized and shaped to be received within the channel ofthe bushing to apply a radially outward pressure to the arms such thatthe arms engage the windows of the capsule, the plurality of engagingelements extending laterally outward from a portion of the core memberdistal of the locking portion such that, each of the engaging elementsengage a corresponding one of the arms to deform the arms radiallyinward and out of engagement with the windows of the capsule.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partially cross-sectional side view of a device accordingto an exemplary embodiment of the present invention;

FIG. 2 shows a cross-sectional side view of a release mechanism of thedevice of FIG. 1;

FIG. 3 shows a lateral cross-sectional view of the release mechanism ofFIG. 1, along the line A-A;

FIG. 4 shows a cross-sectional side view of a release mechanismaccording to another exemplary embodiment of the present invention; and

FIG. 5 shows a cross-sectional side view of a release mechanismaccording to yet another exemplary embodiment of the present invention.

DETAILED DESCRIPTION

The present invention may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present inventionrelates to endoscopic devices as well as elongate medical devices usedwithout an endoscope. In particular, the invention relates to a devicein which a distal portion is deployed through a single stage process.Exemplary embodiments of the present invention describe a releasemechanism comprising a core member including an engaging elementextending therefrom to engage arms of a bushing, through which the coremember passes, such that the bushing is released from a capsule of ahemostasis clipping device to deploy a clip as described, for example,in U.S. Publ. Appln. No. 2008/0306491 to Cohen et al. and entitled“Single Stage Hemostasis Clipping Device” and U.S. Publ. Appln. No.2011/0046651 to Cohen et al. and entitled “Multifunctional Core forTwo-Piece Hemostasis Clip,” the entire disclosures of which areincorporated herein by reference. Although the exemplary embodimentsspecifically describe a clipping device, it will be understood by thoseof skill in the art that the release mechanism of the present inventionmay be utilized with any device requiring detachment from a catheter ortube at a location remote from an operator within a living body.

As shown in FIGS. 1-3, a clipping device 100 according to an exemplaryembodiment of the present invention comprises a bushing 102 including aplurality of cantilever arms 104 releasably engaging a capsule 106 whichhouses a clip 108 therein. The device 100 further comprises a coremember 110 coupled to a proximal end 112 of the clip 108. The coremember 110 is slidably received within the capsule 106 and the bushing102 for movement between first and second configurations as will bedescribed in more detail below. In this embodiment, the cantilever arms104 are substantially hook-shaped to engage the windows 128 in thecapsule 106 to releasably couple to the bushing 102 to the capsule 106.The cantilever arms 104 in this embodiment are biased toward acenterline of the bushing 102 so that, when unconstrained, they do notengage the capsule windows 128, de-coupling the capsule 106 from thebushing 102. It will be understood by those of skill in the art,however, that the cantilever arms 104 may be any of a variety of shapesand may be biased toward a position in which they engage the capsulewindows 128 so long as, the arms 104 engage the capsule windows 128before the clip 108 has been deployed. As made clear below, the arms 104are mechanically deformed and pulled out of engagement from the capsulewindows 128 after the clip 108 has been deployed and thus, disengagementdoes not rely solely on the bias of the arms 104. In the firstconfiguration, a proximal portion 124 of the core member 110 is receivedwithin a distal end of a channel 126 of the bushing 102 such that thearms 104 of the bushing 102 are held radially outward in engagement withwindows 128 extending through a proximal end of the capsule 106. Thecore member 110 includes a plurality of engaging elements 130 extendinglaterally outward from a distal end of the proximal portion 124 suchthat when the core member 110 is moved proximally relative to thecapsule 106 into the second configuration, each of the engaging elements130 engages a corresponding one of the cantilever arms 104 to deform thearms 104 radially inward, away from the corresponding window 128. It isnoted that although the embodiment of FIGS. 1-3 depict two engagingelements 130, any number of engaging elements 130 may be used withoutdeviating from the scope of the invention (e.g., one, three, four, etc.)and to aid in disengagement of the bushing 102 from the capsule 106, aswill be described in greater detail with respect to the exemplary methodbelow. Thus, the cantilever arms 104 are released from the capsule 106separating the capsule 106 and the clip 104 from the bushing and theproximal portion of the device 100.

Specifically, the proximal portion of the device 100 includes thebushing 102 a proximal end 114 of which may be coupled to a flexibleinsertion member 118 which extends out of the body to an actuationhandle accessible to a user of the device 100. A distal end 116 of thebushing 102 is coupled to the capsule 106 via the arms 104 as describedabove. In one exemplary embodiment, the bushing 102 is substantiallycylindrical. It will be understood by those of skill in the art,however, that the bushing 102 and capsule 108 may take any shape desiredfor a particular application without departing from the scope of theinvention. The insertion member 118 is an elongated member extendingbetween a proximal end coupled to an actuating handle (not shown) and adistal end connected to the bushing 102. As those skilled in the artwill understand, the insertion member 118 is formed of a materialsufficiently flexible to allow it to be advanced through a natural bodylumen without damaging the tissue thereof and will have a length suitedto the requirements of a procedure being performed. The device 100further comprises a control element 120 extending through the insertionmember 118 between the handle and the clip 108. The control element 120extends through the insertion member 118 and the bushing 102 from aproximal end coupled to the handle to a distal end connected to the clip108 via the core member 110 such that movement of an actuating mechanismof the handle moves the clip 108 between an open and a closedconfiguration via the handle. For example, as the control member 120 ismoved distally relative to the capsule 106, clip arms 122 are extendeddistally from a distal end of the capsule 106. When extended distallyfrom the capsule 106, the clip arms 122 separate from one another (e.g.,under a natural bias) into an open configuration to receive a targettissue therebetween. The control member 120 may be moved proximallyrelative to the capsule 106 to pull the clip 108 back into the capsule106 so that contact between the capsule 106 and the clip arms 122 drawsthe clip arms 122 together into the closed configuration gripping targettissue received therebetween.

The core member 110 includes the proximal portion 124 and a distalportion 132 connected to one another via a frangible link 134 designedto fail when subject to a predetermined load. As discussed above, theproximal portion 124 is sized and shaped to be received within thechannel 126 of the bushing 102 such that the arms 104 are held radiallyoutward in engagement with the windows 128 of the capsule 106. When thecore member 110 is received within the bushing 102, the core member 104forms a plug which pushes the cantilever arms 104 radially outwardmaintaining them in a locked position in the windows 128 coupling thebushing 102 to the capsule 106. The core member 110 further includesclip hooks 136 at a distal end 138 of the proximal portion 124 forreceiving proximal ends 112 of the clip arms 122. The engaging elements130 extend laterally outward from the core member 110 proximally of theclip hooks 136. Each of the engaging elements 130 corresponds to aselected one of the arms 104 and is positioned about a perimeter of thecore member 110 in alignment with the corresponding cantilever arm 104.The engaging elements 130 may extend radially outward from an outersurface 140 of the core member 110 angled proximally relative to alongitudinal axis of the core member 110 such that a tip 142 of eachengaging element 130 is proximal of a point at which the engagingelement joins the core member 110. Each of the engaging elements 130 issized and shaped to engage an opening 144 extending through thecorresponding arm 104 so that, as the proximal portion 124 is drawnproximally relative to the capsule 106, the engaging element 130 isreceived within the corresponding opening 144. Thus, further proximalmovement of the proximal portion 124 draws the arms 104 proximally,deforming the arms 104 and drawing them out of engagement with thecapsule windows 128. The angled configuration of the engaging elements130 ensures that, as the engaging element 130 is received proximallywithin the opening 144, the arms 104 are drawn radially inward out ofengagement with the windows 128 as the engaging elements 130 moveproximally.

So, when a user is prepared to lock and deploy a clip 108, the controlmember 120 is drawn proximally to grip target tissue. The user thendraws the control member 120 further proximally until the tensionapplied to the frangible link 134 via the control member 120 exceeds thefailure level of the frangible link 134, severing the link 134 andfreeing the proximal portion 124 to move proximally through the capsule106 while the distal portion 132 remains within the capsule 106. Drawingthe proximal portion 124 proximally relative to the capsule 106 releasesthe proximal end 112 of the clip 108 from the clip hooks 136 freeing theclip hooks 136 to spring radially outward into engagement with thewindows 128 locking the clip closed over the target tissue. At the sametime, the engaging elements 130 are received within the correspondingopenings 144 of one of the arms 104 to free the capsule 106 from thebushing 102 as described above.

As shown in FIG. 4, a device 200 is substantially similar to the device100 described above, comprising a bushing 202 releasably coupled to acapsule 206 via arms 204 of the bushing 202 and a core member 210slidably received within the capsule 206 and the bushing 202 which movesthe arms 204 of the bushing 202 into and out of engagement with capsulewindows 228 in a manner similar to that described above. Similarly tothe device 100, a proximal portion 224 of the core member 210 is sizedand shaped such that, when received within the bushing 202, the arms 204are moved radially outward into engagement with the capsule windows 228to couple the capsule 206 and the bushing 202 together. Along a distalend of the proximal portion 224, the core member 210 includes engagementelements 230 extending radially outward therefrom such that, when theproximal portion 224 is drawn proximally relative to the capsule 206,the engagement elements 230 engage the arms 204 deforming the arms 204and drawing them out of engagement with the capsule windows 228. Theengagement elements 230 of this embodiment are sized and shaped tointerlock with correspondingly sized and shaped arms 204. For example,proximal-facing surfaces of the engagement elements 230 according tothis embodiment are curved to form concave surfaces 246 which face thecantilever arms 204. The arms 204 according to this embodiment arecorrespondingly convexly shaped such that when received within theconcave surfaces 246, the arms 204 and the engaging elements 230 areinterlocked ensuring that the arms 204 are deformed radially inward andout of engagement with the capsule windows 228 as the proximal portion224 is moved proximally past the proximal end of the capsule 206.Although the exemplary embodiment specifically describes and showscorrespondingly curved engagement elements 230 and arms 204, it will beunderstood by those of skill in the art that the engagement elements 230and the arms 204 may have any of a variety of corresponding shapes solong as the engagement elements 230 interlock with the arms 204 todeform the arms 204 and draw the arms 204 out of engagement with thecapsule windows 228.

As shown in FIG. 5, a device 300 according to another exemplaryembodiment of the present invention is substantially similar to thedevices 100, 200 described above, comprising a bushing 302 releasablycoupled to a capsule 306 via arms 304 received in windows 328 of thecapsule 306 and a core member 310 slidably received within the bushing302 and the capsule 306 for moving the aims 304 of the bushing 302 intoand out of engagement with capsule windows 328. Similarly to the coremember 210, the core member 310 includes a proximal portion 324 which,when received within the bushing 302, moves cantilever arms 304 radiallyoutward to engage the capsule windows 328. Along a distal end of theproximal portion, the core member 310 includes engagement elements 330for engaging the cantilever arms 304 to deform the arms 304 radiallyinward and out of engagement with the capsule windows 328 as theproximal portion 324 is drawn proximally relative to the capsule 306.The engagement elements 330 also include a curved surface 346 facing thebushing 302. However, the curved surface 346 is not sized and shaped tointerlock with the cantilever arms 304 in the same manner as in thedevice 200. Rather, the curved surface 346 here is treated with amaterial having adhesive qualities such that when the surface 346 of theengaging element 330 comes into contact with the arms 304, the arms 304adhere to the engagement element 330 from a distal end 348 of the arms304 toward a proximal end 350 thereof such that the arms 304 are drawnradially inward out of engagement with the capsule windows 328. As wouldbe understood by those skilled in the art, the material with which thecurved surface 346 may be treated may be any suitable biocompatibleadhesive material. Alternatively, the material may be a polymer whichmimics adhesive behavior. In an exemplary embodiment, the material maybe a biocompatible pressure sensitive adhesive (PSA) having elastomericproperties. Specifically, the engagement elements 330 may be coated withthe PSA while the bushing arms arm are coated with a correspondingadherent, as those skilled in the art will understand. The adherentcoating on the arms 304 may be configured to exhibit the requiredadhesive properties at room temperature. In another embodiment, thematerial may be a polymer configured to mimic adhesion instead of beinginherently adhesive. Specifically, the arms 304 may be coating with agummy/flexible substrate (e.g., an elastomer with mechanical propertiessimilar to those of biological tissue) and the engagement elements 330may be coated with a micropatterned layer of polymer material (e.g.,flowable silicones including but not limited to silicones that have beenthinned to be rendered flowable, etc.). The micropatterned layer on theengagement element 330 (not shown) creates a mechanical interlock withthe substrate on the bushing arm 304 to aid in retraction of the arms304 radially inward and out of engagement with the windows 328. In someembodiments, the engaging elements 330 can be secured onto, over oraround the arms 304 of the bushing 302 to assist in the removal of thearms 304 from the capsule windows 328.

In another embodiment of the invention, the arms 104, 204, 304 may bebiased to fold or collapse once a force from the engaging elements 130,230, 330 reaches a predetermined level. Specifically, a shape of thearms 104, 204, 304 may be biased to include a fold line permittingfolding thereof.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the structure and themethodology of the present invention, without departing from the spiritor scope of the invention. For example, the bushing 102, 202, 302 mayinclude any number of arms 104, 204, 304 extending therefrom. In anotherexample, a material thickness and/or width of the arms 104, 204, 304 maybe altered to be more flexible or softer in certain portions. Thus, itis intended that the present invention cover the modifications andvariations of this invention provided that they come within the scope ofthe appended claims and their equivalents.

What is claimed is:
 1. A tissue clipping device, comprising: a distalportion sized and shaped for insertion into a body lumen, the distalportion including a clip having a first clip arm, a proximal end of theclip movably housed within a lumen of a capsule extending longitudinallyfrom a proximal end to a distal end such that the clip is movablerelative to the capsule between a tissue receiving configuration inwhich the first clip arm extends distally from a distal end of thecapsule in a biased open position and a tissue gripping configuration inwhich the first arm is retracted proximally within the capsule, thecapsule including a first window extending laterally through a proximalend thereof; a bushing extending from a proximal end to a distal end andincluding a channel extending therethrough, the distal end including afirst bushing arm extending distally therefrom such that the firstbushing arm is releasably engagable with the first window of thecapsule; and a core member received within the capsule and coupled to aproximal end of the clip arms, the core member including a lockingportion and a first engaging element, the locking portion sized andshaped to be received within the channel of the bushing to apply aradially outward pressure to the first bushing arm such that the firstbushing arm engages the first window of the capsule, the first engagingelement extending radially outward from a portion of the core memberdistal of the locking portion such that the first engaging elementsengages the first bushing arm to deform the first bushing arm radiallyinward and out of engagement with the first window of the capsule. 2.The device of claim 1, further comprising a second window on the capsuleand a second bushing arm formed on the distal end of the bushing, thefirst and second bushing arms being positioned such that a correspondingone of the first and second bushing arms releasably engages acorresponding one of the first and second windows.
 3. The device ofclaim 2, further comprising a second engaging element formed on the coremember, the second engaging element extending radially out of the coremember distal of the locking portion such that each of the first andsecond engaging elements engages and deforms a corresponding one of thefirst and second bushing arms radially inward and out of engagement withthe first and second windows of the capsule, respectively.
 4. The deviceof claim 3, wherein the first and second engagement elements are angledwith respect to a longitudinal axis of the core member such that a tipthereof is pointed toward a proximal end of the device, the engagingelements being sized and shaped to be received within correspondingholes extending through each of the first and second bushing arms. 5.The device of claim 3, wherein the first and second engagement elementsand the first and second bushing arms are correspondingly sized andshaped such that the first and second engagement elements and the firstand second arms interlock with one another.
 6. The device of claim 3,wherein the first and second engagement elements comprise respectiveconcave proximal surfaces which are shaped to interlock with the firstand second arms, respectively.
 7. The device of claim 1, wherein thefirst engagement element is treated with a material having adhesiveproperties to adhere to the first arm.
 8. The device of claim 7, whereinthe material is one of an adhesive and a polymer.
 9. The device of claim1, wherein the core member includes a proximal portion and a distalportion connected to one another via a frangible link configured to failwhen subject to a predetermined load, the locking portion and the firstengagement element extending along the proximal portion so that, whenthe frangible link is severed, the distal portion remains within thecapsule while the proximal portion is moved proximally relative to thecapsule.